Human Anaplasmosis Statistics

From 1996 to 2013, 4,555 cases of human anaplasmosis (HA) (formerly known as human granulocytic ehrlichiosis) were reported in Minnesota. In 2013, 627 confirmed or probable anaplasmosis cases (11.7 cases per 100,000 population) were reported. This represents a 24% increase from the 507 cases in 2012, although it is considerably lower than the record 788 cases in 2011. Despite these fluctuations, the trend is an increase in yearly case totals over time.

The number of anaplasmosis cases has been increasing since the first cases of HA were reported in Minnesota in the mid-1990s. A variety of factors, including increasing physician awareness, increasing infection rates in ticks, and expanding tick distribution, may have led to this trend.

The HA cases in 2013 ranged in age from 2 to 93 years; the median age (56 years) was greater than that of Lyme disease (42 years). In 2013, 63% of HA cases were male.

On this page:
Charts and graphs
Annual summaries

Charts and Graphs


Most HA cases report likely exposure to blacklegged ticks in the same east-central and north-central Minnesota counties where the risk of Lyme disease is greatest.

Annual Summary Statistics

Updated Tuesday, July 28, 2015 at 01:27PM